asthma

Prenatal Vitamin D Supplementation: Could it Prevent Asthma?

High-dose vitamin D supplementation during pregnancy does not affect the risk of asthma and recurrent wheeze in offspring at risk for asthma, according to the results of a recent study.1

Previous analyses by the team of researchers suggested that prenatal vitamin D supplementation could be associated with a significant reduced risk of asthma and recurrent wheeze in offspring through age 3 years.2

In order to examine the long-term effects of this intervention, the researchers conducted a follow-up study to their 2017 analysis in which 1477 pregnant women were randomly assigned to receive 4000 IU/d or 2400 IU/d vitamin D3 or placebo. All participants also received a daily vitamin containing 400 IU/d vitamin D3. That study showed a 25% reduction in the risk of asthma and recurrent wheeze at 0 to 3 years (adulted odds ratio 0.74, 95% CI, 0.57-0.96, p = 0.02).

In the follow-up study, offspring were followed until age 6 years. Overall, they observed no effect of prenatal vitamin D supplementation on risk of asthma or recurrent wheeze in any of the groups, regardless of the mother’s 25-hydroxyvitamin D level during pregnancy.

“Vitamin D supplementation during the prenatal period alone did not influence the 6-year incidence of asthma and recurrent wheeze among children who were at risk for asthma,” they concluded.

—Michael Potts

References:

  1. Litonjua AA, Carey VJ, Laranjo N, et al. Six-year follow-up of a trial of antenatal vitamin d for asthma reduction [published online February 6, 2020]. NEJM; 382:525-533. doi: 10.1056/NEJMoa1906137. Accessed February 6, 2020.
  2. Wolsk HM, Chawes BL, Litonjua AA, et al. Prenatal vitamin D supplementation reduces risk of asthma/recurrent wheeze in early childhood: A combined analysis of two randomized controlled trials. PLoS One. 2017 Oct 27;12(10):e0186657. doi: 10.1371/journal.pone.0186657. Accessed February 6, 2020.